How Michel came to his revolutionary concept of ORGANIC VAT.

Here, Michel highlights key plants suitable for temperate climates, not forgetting the esteemed Indigofera tinctoria. We're taken into his atelier to see the cultivation of Strobilanthes cusia, preparing for spring, and discusses the potential of woad and Persicaria tinctoria for creating the iconic blue indigo dye.

Dive into the varied aspects of indigo with Michel Garcia as he takes us through traditional to revolutionary methods in his latest tutorial. For the first time, he reveals his crushed-and-dried leaves technique, a simple yet fast approach that is changing the indigo dyeing process.

We delve into the 1-2-3-4 method, a straightforward technique for preparing an indigo vat using crushed and dried leaves. This method is critical for facilitating the interaction between the enzyme and the precursor within the leaves to produce indigo.

When I began exploring indigo dyeing, common belief held that fermentation was essential to access indigo from the plant. However, Michel's experiments showed otherwise. Simply crushing fresh leaves and drying them quickly turned them blue, simplifying vat preparation. Some argued that compost fermentation was needed for indigo dissolution due to bacterial action, but I found a pinch of fruit sugar could replace this complex process.

We're testing a special compost from Persicaria leaves provided by Marianne Gorostiza, which promises stronger dye than just crushed and dried leaves. The 1-2-3-4 process uses 80 grams of compost, 60 grams wood ash, 40 grams lime, and 20 grams of fruit sugar added after a reaction between the lime and ash. This mixture, ready in minutes without traditional fermentation, demonstrates an easy way to prepare a potent indigo vat.

On our second day, we revisited two vats from yesterday: one with crushed and dried Isatis tinctoria (woad) leaves and another using compost from Persicaria tinctoria leaves. Initially hot to the touch, these vats were not optimal for silk dyeing, which turned a bit greenish due to the heat. Overnight, the vats cooled and matured, suggesting a better practice might be to prepare vats a day in advance for optimal results.

We're delving into making indigo extract, a process distinct from the crush-and-dry method and composting, known from ancient times and Renaissance Europe. This tutorial introduces a third method, the infusion technique. It involves soaking dry Indigofera tinctoria leaves in warm water at about 55°C for an hour, filtering the infusion, and then aerating it to precipitate indigo particles. This process, while simple, efficiently separates the pigment from leaf cellulose.

Using this press, we can process several kilos of plants at once, expecting to produce around 50 grams of indigo pigment, possibly more. This press efficiently compacts the plant matter into a cake, setting us up for the aeration step. Aeration is crucial; by introducing air through a pump, we cool and oxygenate the liquid, facilitating the transformation of the yellow infusion to a dark green, then bluish hue. After aeration, we add clay as a flocculant to aggregate the tiny indigo particles, making them easier to filter out.

​We started with 1.2 kilos of indigo powder soaked in 55°C water for an hour, then strained it to obtain a clean liquid. After aerating and adding 50g of clay (sepiolite), we allowed the blue particles to settle for three hours, removed the yellow supernatant, and filtered the remaining blue mud through cotton to get indigo paste. This paste can be used for dyeing as-is or dried for storage.

Michel talks about history of indigo dye.

Theory and demo of organic indigo vats. Michel showes first 1-2-3 vat with indigo paste and fructose.

Lime cycle. Understanding lime is a crucial question, important for success of your vat.

1-2-3 vat starting with the  powder

Understanding the properties of indigo and its impurities is crucial. Waxes from the plant's leaves can precipitate during the dye extraction process, potentially aggregating the indigo and making it difficult to dissolve. To ensure a smoother process, hot water can be used initially to soften the wax. For a more effective solution, converting the wax into soap with potassium hydroxide (made from wood ash and lime) helps. This technique allows for the indigo particles to remain suspended in the solution, facilitating a more efficient dye vat

Highlighting the flexibility and efficiency of the ferrous vat underscores the importance of understanding chemical reactions over adhering to old beliefs about dye processes. This approach simplifies the dyeing process, ensuring vibrant and lasting colors. Tomorrow, we'll explore scaling up our dye vats for larger textiles, further demonstrating the practicality and effectiveness of modern dye techniques grounded in historical knowledge.

Detailed chemistry of indigo plant and indigo vat

1-2-3 organic vat, middle-scale. Making and meintenance of the vat. How to revitalize 3-years old vat? Detailed demo.

Indigo and mordants. Lecture and demo.

The basics of dyeing wool with indigo